Double Strand Nugget Necklace

Gorgeous old graduated double strand nugget necklace, natural turquoise - blue/green -pictures don’t quite capture the color, I gasped when I got this one - quite heavy stones, larges nuggets at center about the diameter of a quarter a little larger -consistency in color and quality through all the stones - hundreds of carats of natural nugget - any ideas on mine - provenance purchased 1956 New Mexico. Strung on thread with deteriorating wrap.

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It is difficult to tell from the picture, but it appears to be streaks of iron pyrite in the nuggets, the date rules out chinese, so possible Morenci.

Thanks , haven’t been on here in awhile, no pyrite, choclate to near black on the matrix, very very hard and heavy - more greenish blue than blue.